If politicians claim that the public has nothing to worry about metadata surveillance is harmless because the practice not pry into the content of private communications, they’re wrong.

That’s the gist of a paper this week by Ann Cavoukian, Ontario privacy commissioner, who called for better safeguards and judicial oversight on online government surveillance programs to protect individual privacy rights.

Metadata surveillance programs gather and analyze private sector metadata, according to her paper, A primer on metadata: Separating fact from fiction. The practice enable federal agencies to “instantaneously” create a digital profile of the “life of anyone swept up in such a massive data seizure.”

Cavoukian released the paper in the light of the controversy raised last month by exposure of the United States National Security Agency’s Prism program which enabled federal authorities to cull massive amounts of private communications data from U.S.-based companies that include Internet service providers, search engines, social network sites and cloud-based service providers. The NSA has claimed that the surveillance was being carried out to preempt terrorist activities and that conversations being spied on where not those of U.S. citizens living in the country.

The privacy chief characterized metadata as “digital crumbs” generated by communication devices used by individuals such as landline telephones, mobile phones, computers and tablet devices. They could include information revealing the time and duration of a communication, particular devices used, addresses or numbers contacted.

Sen. Dianne Feinstein, senior member of the U.S. senate intelligence committee, had also said the surveillance was “just metadata” and that no content was involved.

“The inference is that you shouldn’t be worried about the state’s access to metadata because it is of little value – only listening to your telephone calls or accessing the actual content of your communication would be invasive of your privacy…Wrong!” said Cavoukian. ”The data could also reveal people’s political or religious affiliations, as well as their personal and intimate relationships.”

Once the “detailed picture” of the person’s digital profile is produced, their identities can be easily determined with a few additional data sources, she said.

“When privacy is compromised…it can provide the government with tremendous amount of power over its people,” Cavoukian said quoting Daniel Solove Washington University Law School professor.

She also labeled as “false and misleading” the notion that individuals who have “nothing to hide” should not be concerned about their privacy. The state owes its legitimacy to its citizens and therefore it must be transparent so that it can be held to account for its actions.

In the U.S., a review of the NSA’s surveillance programs has become a top priority and the Civil Liberties Oversight Board will be releasing a public report about the legality and propriety of the metadata program.

In Canada, national Privacy Commissioner Jennifer Stoddart is looking into the privacy implications for Canadians of surveillance programs. Data protection commissioners in Europe and other countries have also voiced their concerns over the issue.

Greater transparency and accountability on the part of government bodies conducting such surveillance, is necessary, Cavoukian said as she called on citizens, politicians, business leaders, privacy experts and security officials to band together to call for the protection of privacy in communication.